marathag
Banned
Part of the advantage besides high ROF, is that a dud wouldn't even noticed, as it would be cleared the same way as every other round. Everything else, pilot would need to hit the charge solenoid to manually cycle the gun
Part of the advantage besides high ROF, is that a dud wouldn't even noticed, as it would be cleared the same way as every other round. Everything else, pilot would need to hit the charge solenoid to manually cycle the gun
marathag
Banned
The US Ordnance staff for MGs, in some ways was as bad as the USN Torpedo group.
Almost any other country, they would have been at worst, shot- to re-assigned counting boxes in the Aleutians at best The list of failures was long.
I'd be concerned about battle damage to the line(s) rendering the gun(s) inoperative. I do like the idea of being able to clear jams without difficulty; perhaps a small hydraulic/electrohydrdaulic reservoir ("bottle") for each gun? (Unless even a recoil-op gun would clear automatically?)
One other thought: interconnect the guns, akin the Gast (which would also clear jams). Too much to ask?
Would requiring a working hydraulic system increase the chance of battle damage rendering the guns inoperative? Maybe. But if you take damaging hits in a fighter you are likely more interested in returning home if you are able to make a run for it rather than trying to shoot at something. Hopefully escorted by a wingman or three whos' guns are working just fine.
You're not wrong prima facie. However, it occurs to me rounds that don't do "run for home" damage might still do enough to put the guns u/s. Is it likely? IDK, maybe not. Maybe hydraulic drive would be as robust as the P-39's driveshaft proved. I just prefer to avoid the hazard, when there are other options. Besides, wouldn't a recoil-operated gun be simpler, & so less prone to failure even absent hostile fire? And isn't that a good thing? You know that maxim: KISS.
Personally, I have a bit of an obsession for revolver canons (or in this case a revolver HMG) and love the idea of putting a couple to replace the 4+1 setup of the P-38. Believe it or not, I have even considered this already for the ATL Lightning but due to the speed of weapon development IOTL I have decided it likely makes more sense to hold off until post-war appearance of the ATL F-81 to upgrade the guns.
The choice between gas-operated and externally driven guns boils to balancing the benefits of each. Externally driven gives the reliability advantage, as already mentioned, in that it can self-clear any misfires without a break in cycle. It also simplifies the mechanics of the weapon and could likely speed up development. However, it adds weight and bulk to system. Also, externally driven guns tend to take a few cycles to get up to speed, although revolver-types get up to full speed faster than rotary-types. Finally, as mentioned, there is a potential risk of the driving motor (whether electric or hydraulic) failing and thereby rendering the entire system inoperative. Gas-driven weapons can be made lighter and do not have the weight and complexity of the external drive system but their internal mechanics tend to be more complicated. They normally cannot self-clear failed rounds, but could theoretically be made to do so (I am not sure if this has ever been done) by having the gas turn a flywheel which sustains rotational velocity. Of course, in this case, the advantage gas-operated systems have of being full-speed on the second round may be negated because it would take a few rounds for the flywheel to gain enough energy to cycle full-speed.
Regardless of the system, the P-38 may have trouble gaining the advantage of mounting fewer weapons--more ammunition. The nose is pretty narrow and until linkless ammunition feed is fully developed it is difficult, or impossible, to feed a single gun from multiple rows. I suppose the magazines could be designed to be longitudinal to the A/C behind the weapons with a 90 degree bend into revolving breech but even this can be tricky with standard linked ammunition. Then there is the complexity of de-linkers for such a system. In fact, in the modern M134 Minigun, it is the de-linker more than other part which was the most difficult to develop and is considered the most important (and sensitive) part of the weapon system.
The choice between gas-operated and externally driven guns boils to balancing the benefits of each. Externally driven gives the reliability advantage, as already mentioned, in that it can self-clear any misfires without a break in cycle. It also simplifies the mechanics of the weapon and could likely speed up development. However, it adds weight and bulk to system. Also, externally driven guns tend to take a few cycles to get up to speed, although revolver-types get up to full speed faster than rotary-types. Finally, as mentioned, there is a potential risk of the driving motor (whether electric or hydraulic) failing and thereby rendering the entire system inoperative. Gas-driven weapons can be made lighter and do not have the weight and complexity of the external drive system but their internal mechanics tend to be more complicated. They normally cannot self-clear failed rounds, but could theoretically be made to do so (I am not sure if this has ever been done) by having the gas turn a flywheel which sustains rotational velocity. Of course, in this case, the advantage gas-operated systems have of being full-speed on the second round may be negated because it would take a few rounds for the flywheel to gain enough energy to cycle full-speed.
Regardless of the system, the P-38 may have trouble gaining the advantage of mounting fewer weapons--more ammunition. The nose is pretty narrow and until linkless ammunition feed is fully developed it is difficult, or impossible, to feed a single gun from multiple rows. I suppose the magazines could be designed to be longitudinal to the A/C behind the weapons with a 90 degree bend into revolving breech but even this can be tricky with standard linked ammunition. Then there is the complexity of de-linkers for such a system. In fact, in the modern M134 Minigun, it is the de-linker more than other part which was the most difficult to develop and is considered the most important (and sensitive) part of the weapon system.
Changing gears a little, I have been outlining the next few chapters of the TL and think I am finally ready to move forward again, which is great news.
Also, I have been playing with Turbo-Compounding (on paper anyway) in different systems just to build my understanding and get a better idea of exactly how it works in series as part of a complete powerplant system. Before adapting the ATL V-1710-F29 (? I think that was the model designation I finally settled on, although maybe that was the one with the larger prop reduction for use with the H-S three blade Hydromatic and F32 was what I settled on for the final version, I think I have been inconsistent with this in the narrative) to be Turbo-Compound for the XP-81 I decided to see what it looks like with some modern aviation powerplants. One big thing I have noticed with this is that the Exhaust Pressure:Manifold Pressure (Pe : Pm) ratio is one of, if not the, key factors in how much power a theoretical Blowdown turbine can recover. This means, that Turbo-Compounding provides very little benefit to a Naturally Aspirated engine, especially when not under full throttle (Pe : Pm >1.0). Still, even assuming a N-A Lycoming IO-540-AB1A5 in a Cessna 182T at 6000 ft. MSL, it looks like a properly tuned and sized Blowdown Turbine can add as much as 19 HP at Max. Cruise (80% power settings, 2400 RPM, 23 in.Hg Pm), or about a 10% increase in Net Thrust HP (including reductions for turbine, transmission, and propeller efficiencies) with a reduction of about 9% in Net Thrust Specific Fuel Consumption (SPC per Thrust HP, which is not the same as the Brake Specific Fuel Consumption, or Fuel used per HP produced by the engine which remains the same). This is figuring for zero back-pressure in the exhaust at Turbine exit but also assuming everything else in the system is tuned absolutely perfectly for those exact conditions. Realistically, since the turbine would need to be able to operate under a variety of conditions, this number would probably be reduced by a bit.
The take away from doing this is that to get full performance and power curves for the theoretical ATL T-C Allison I need to decide between best economy settings (better range and endurance) or best performance settings (max speed), or something between. Given the requirements for the XP-81 (Very Long Range Escort fighter) I am inclined toward the former, as the Water-Injected F32 engine in the ATL P-38J/K already has plenty of Max.Performance and even tuned for best econ. the T-C engine should increase the total Power a bit.
Also, I have been playing with Turbo-Compounding (on paper anyway) in different systems just to build my understanding and get a better idea of exactly how it works in series as part of a complete powerplant system. Before adapting the ATL V-1710-F29 (? I think that was the model designation I finally settled on, although maybe that was the one with the larger prop reduction for use with the H-S three blade Hydromatic and F32 was what I settled on for the final version, I think I have been inconsistent with this in the narrative) to be Turbo-Compound for the XP-81 I decided to see what it looks like with some modern aviation powerplants. One big thing I have noticed with this is that the Exhaust Pressure:Manifold Pressure (Pe : Pm) ratio is one of, if not the, key factors in how much power a theoretical Blowdown turbine can recover. This means, that Turbo-Compounding provides very little benefit to a Naturally Aspirated engine, especially when not under full throttle (Pe : Pm >1.0). Still, even assuming a N-A Lycoming IO-540-AB1A5 in a Cessna 182T at 6000 ft. MSL, it looks like a properly tuned and sized Blowdown Turbine can add as much as 19 HP at Max. Cruise (80% power settings, 2400 RPM, 23 in.Hg Pm), or about a 10% increase in Net Thrust HP (including reductions for turbine, transmission, and propeller efficiencies) with a reduction of about 9% in Net Thrust Specific Fuel Consumption (SPC per Thrust HP, which is not the same as the Brake Specific Fuel Consumption, or Fuel used per HP produced by the engine which remains the same). This is figuring for zero back-pressure in the exhaust at Turbine exit but also assuming everything else in the system is tuned absolutely perfectly for those exact conditions. Realistically, since the turbine would need to be able to operate under a variety of conditions, this number would probably be reduced by a bit.
The take away from doing this is that to get full performance and power curves for the theoretical ATL T-C Allison I need to decide between best economy settings (better range and endurance) or best performance settings (max speed), or something between. Given the requirements for the XP-81 (Very Long Range Escort fighter) I am inclined toward the former, as the Water-Injected F32 engine in the ATL P-38J/K already has plenty of Max.Performance and even tuned for best econ. the T-C engine should increase the total Power a bit.
Here are two views of the magazine and ammunition feed for the two M39 20mm revolver cannons installed in the F-5 fighter. The F-5 has a long narrow nose similar to the P-38. The ammunition feed takes a few twists in its travel from the long narrow magazine where the belts are stacked in layers to where it's fed into the rotary breech. I think it's linked ammo but I'm not certain.
I think this makes a good case for externally powered guns for the breech and ammunition feed. It's a proven way (with hindsight but not ASBish) to fit the magazines longitudinally and still be able to feed the guns.
That's great news that you're almost ready with the next chapter EverKing. I'm certain it will be greeted with great interest. And the turbo-compound engines are a big plus for that longe range hours long cruise for improving fuel economy.
KISS is a good rule providing the KISSed item does the job sufficiently well. Consider that we are reducing the number of guns in a fighter (for example P-38 5 to 2, P-51 6 to 2) you need those guns to be as reliable as possible. You go into a fight in your older P-38 and take a shot if 1 gun jams you still have 4 others working. With the 2 revolver guns if one jams you lose half your firepower. Good luck if both jam which could happen in high-G maneuvering. And you could be too busy to work the jams free immediately.
Externally powering the guns and their feed greatly increases the reliability of the weapons making them more effective and likely reducing the chance of damage to your plane in combat. Combat damage is an important consideration but in this situation I think it's secondary.
Twin M39s have been in the back of mind for quite some time should the F-81 survive into the 60's (perhaps as the Turbo-Lightning I played around with a few months back). That installation in the F-5 is exactly what inspired my potential installation solution for the P-38 family (including the XP-81 if mounted in the nose).
As for a similar revolver design using .50 BMG I do not see any real benefits over the AN/M3. The Lightning can easily mount 4-6 AN/M3 (and can squeeze 8 in there if you're clever), at 1100-1200 rpm/gun that is a total weight of fire of at least 4400 rpm and up to 7200 rpm (for a six gun installation). The revolver system may be able to increase the RoF to as much as 1800-2000 rpm/gun but added weight and complexity would likely reduce this installation to 2-3 guns for a total of 3600-6000 rpm. In addition, a failure of a single weapon--assuming similar failure rates for both systems which may not be entirely accurate but we can't judge that without extensive testing--in the AN/M3 load has less impact in the total available weight of fire than a similar failure would have in the revolver HMG setup.
I think if you do want to go with revolvers, you go big or go home. Install a full twin M39 20mm system. The weapons themselves are shorter than the A/N-M2 20mm Hispano, so we know they will fit. The reduction in total-net RoF should be more than made up for by the net weight of fire (in oz./sec).
I believe you and I have been thinking along the same lines. And I largely agree with your conclusions. For a realistic WW2 armament fit an earlier (say 1942) development of the M2-AN3 would be a very good thing. Regarding the fit of 4 or 6 of them in the P-38s that is a hell of an increase in firepower.
The only advantages I can offer for my .50 revolver HMG is firing time won't be shortened as much because with only two guns there is more room for larger magazines. The other plus is I think there would be an increased muzzle velocity with the revolver HMG. That could be a significant factor if it's a large increase but I admit this is only speculation on my part.
If you have installed 4 M2-AN3 HMG in the nose how large a magazine per gun can be fitted? These guns would shoot 20 rounds a second or so. With the OTL 500 round magazine is 25 seconds of firing time sufficient? If we put in 6 guns is there still room for the 500 round magazines?
Actually I think 25 seconds is adequate for most circumstances and the 4 or 6 M2-AN3 fit would have been a good thing in 1943 and onward.
Regarding the M39 it would be totally kick ass for WW2. Big or small no enemy airplane would withstand a well aimed burst from those beasts. One shot one kill. And the effective range would be much increased if the gunsight is matched to the weapon. Could a P-38 take the weight and power requirements of 2 M39s?
But I think we would need some assistance from our leather winged friends to see M39s in use during WW2.
Me, too. If I could figure out how, I'd have revolver *MG in ACW. (There were enough Colt copyists, & a few designers of "explosive engines" {pre-Otto IC}...
)You've captured it nicely. (And I should've summarized my views much the same way...
)That's an idea I don't think I've ever seen before.
The nearest I've come across is the Gast, which cross-connects; that risks putting both u/s if the connection link is damaged (one reason it never got popular).And, as usual, you've nailed the practical side, where I'm dreaming of .50 *BrKAS-armed YB-40s...
( ) (Or B-39s. )I can think of one, & that's the greatly increased ROF. Not so much for the delivered weight of fire (not trivial) but for the greater probability of hitting. That's less important in prop v prop fights, but in jet v jet... That said, 4x20mm might be superior, but USAAF/USAF might take a bit of convincing postwar. It'd also be of use for defending bombers--& here, it makes me wonder if the difference would (could?) push back the introduction of P-51s (if adopted in time). (I'm going to presume these guns don't appear until around the same time as the MG213, so that doesn't pertain.)
I'm not seeing why, TBH.
Agreed. I'd suggest there's an issue of pilot training involved, too: hosing off ammo with the OTL M2 was problematic enough; 1sec bursts from these would be extravagant: training to 'squeeze & release" (& not hold down) might be required.
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And then there's the story of the USN and the British Hispano 20mm gun. The US obtained some examples and the plans. When redrawing the plans for manufacture in the US whoever did it made the chamber slightly longer. That meant that the rounds seated farther away from the firing pin and that made the guns unreliable because the rounds might or might not get a solid primer strike. They dinked around with this (IIRC) years, to the point that they had 40 million rounds of ammunition and no dependable guns to fire them in.
First half of the next chapter is nearly ready. I will be posting it as parts A and B, with A being the shorter of the two and really just there to set the stage and provide some exposition. I am doing this for several reasons:
- it will get something posted to keep this TL alive
- it will explain some of what happens in part B without needing to break the narrative
- it will allow us a little time to discuss what is revealed between the two parts
Ch.36(a) - Außerordentliche Mittel (Jul/Aug 1944)
22 July 1944
1./SG 1
Flugplatz Hotsten, Westphalia, Prussia, Germany
The unit, formerly attached as a subordinate to the I Gruppe of Jagdgeschwader 1, was once more independent. After continued losses over the previous six months the attrition had become untenable and they had been pulled back from Dortmund to re-organize at the little used Hotsten airstrip near the Lower Saxony border. Of the original Sturmbock pilots from the previous fall, only four remained.
The old saying was, “Außerordentliche Übel erfordern außerordentliche Mittel” and these certainly were times of extraordinary ills. Oberleutnant Gerhard Limberg knew how desperate the air war over the Continent had become but even if he had not the evidences were parked along the grass field in front him: sixteen new airplanes of three different types, cobbled together like old shoes from bits found in the parts bins. Truly extraordinary remedies.
All sixteen aircraft were experimental, having been rushed to 1 Sturmstaffel for immediate use and evaluation. Rumor was that they had not even undergone complete flight testing—instead, after being found generally airworthy, the High Command determined that they would be best evaluated by the experienced pilots who would fly them. Officially, they were told it was to ensure the highest quality of machine to forward units once the most experienced pilots certified them but unofficially it was understood by Limberg and his comrades that there were no longer enough skilled pilots to supply full compliments to both active units and the test branch.
Eight were Focke-Wulf 190s. Six of these looked more-or-less similar to the Antons with which they were accustomed, although Limberg noted they were slightly longer in the nose with four-bladed airscrews and had a small scoop protruding from below and behind the cowl, just fore of the wing roots. The remaining two 190s were set apart by even longer noses as well as lengthened and broadened tails but their most striking features were the large pouch-like scoops under the fuselage. From this—or perhaps into this—pouch were partially exposed ducting running to and from the engine cowl.
If the odd appearance of the pouched 190s caught the attention of the pilots, it was quickly over-shadowed by the remaining eight airplanes—or, rather, four airplanes, Limberg corrected himself—for what at first he had taken to be eight new Messerschmitt 109s were actually four individual airplanes each made by joining two 109s together.
“Mein Gott,” Oberleutnant Hans Weik muttered just loud enough for Limberg to hear. The tone was clear and Limberg knew what was left unsaid.
They expect us to fly these into the fight?
8 August 1944
Those pilots with more experience in the Messerschmitt were given the 109 Zwilling aircraft. They were twin engine, twin fuselage heavy fighters with the single pilot in the left fuselage and the cockpit removed and faired over on the right side. They were quick, temporary, measures to get aircraft with firepower to bring down the American viermots with enough speed to outrun their Lightning and Mustang escorts.
The staffel had already lost one to an accident when the pilot, unused to dual-engine flying, lost the left engine on final and cartwheeled into the ground.
Limberg had been allowed to try some of the new Focke-Wulfs. The shorter-nosed variants, Bruno, were almost the same as his old Anton but with the engine replaced by a new BMW 801J Triebwerksanlage originally intended for the Junkers 388. These air-cooled radials were different from the standard 801s by being fitted with a Turbolader behind the engine, the charge air cooled by a small intercooler in the external scoop under the Kraftei. Three of these Brunos were additionally enhanced by having slightly larger wings with an extra two square meters of area for better high-altitude performance and also had pressurized cockpits.
The other two, which were officially Cäser models but which the pilots had started to call Känguruh because of the large pouch under the fuselage, had the air-cooled BMW engine replaced with the massive Daimler DB 603 inverted V-12. These were also fed by a large intercooled Turbolader, with both the turbo and the intercooler housed in the large pouch. The exhaust stacks were combined on each side into long hot ducts which ran externally along the nose and then under the upper wing fillet and back out the rear of the wing and down to the pouch. The intake air ducts were likewise exposed from the front of the pouch from where they went back up into the lower engine cowling to feed the engine. These were also pressurized but lacked the larger wings of the three pressurized Bruno airplanes.
Of these, Limberg preferred the Bruno. While the Caesar was slightly faster, it also handled differently and had the tendency to nose over at lower speeds. The Bruno, on the other hand, flew much the same the Anton but with added assurance of the significant power increase and, the case of those with pressurized cockpits, more comfort where they would be needed above 6 kilometers.
Two of the Brunos were out-of-service, both having suffered engine damage as a result of turbo failures, and were awaiting replacements. In the meantime, Limberg had claimed one of the pressurized B-4 airplanes as his own, now painted with his White-8, and he worked with his maintenance crew to apply a Rüstastz kit from his last Sturmbock to the airplane. The work included replacing the 7.92mm MG 17 cowl guns with 13mm MG 131s and the 20mm MG 151/20 outer-wing cannons with 30mm MK 108s as well as adding the heavy 30mm canopy and windscreen armor and 5mm cockpit armor. The resulting airplane, Fw.190B-4/R1, was one that Limberg felt may actually have a chance at fulfilling its role as a bomber destroyer and still get him home safe from the American fighters—even after adding the weight of the armor and larger guns he was able to push it over 700km/h at 8 km altitude using MW50 boost.
The Kangaroos and Zwillings were even faster. Weik had reported that he pushed one of the Caesars past 720km/h at 7000 meters without over-speeding the turbo, meaning there may be even more power available. Hauptman Walter Rödl had claimed to hit nearly 750km/h in Zwilling Black-3 just two days earlier at 8 km.
Now that they had proven they could fly the experimental aircraft they were being sent back to Dortmund to join the Fw.190 Sturmbocke of II Sturmgruppe of JG 300 to try them in combat.
10 August 1944
61 FS, 56 FG, 65 FW, 8 AF
AAF-150 (RAF Boxted), Essex, England
Captain Donald Hilgert had been back in England for nearly a month now.
After six months back in the States for leave and training when his first tour ended he shipped out in early July to his new assignment as Deputy Squadron Commander of the 61st Fighter Squadron of the 56th Fighter Wing as part of their transition from P-47s to P-38s, the last Group in the 8th Air Force scheduled to do so. Once the 56th is up and operational with P-38s, each Fighter Wing in VIII Fighter Command will be composed of three Groups of P-51s and two of P-38s. With each Wing attached directly to one of the three Air Divisions, then each Group of Bombers will be afforded equal protection.
The transition was scheduled to correspond with the end of tour for most of the existing 56th pilots, allowing them to backfill the needed personnel from P-38 qualified pilots taken from stateside Groups and rotating experienced pilots, like Hilgert, back for a second tour. The remaining P-47 pilots would receive transition training to the P-38 over the four weeks planned from mid-July to mid-August.
The other P-38 Group in the Wing, the 479th, was lucky enough to come with their own aircraft and so received the new P-38K. Hilgert’s 56th Group was not so fortunate. The new airplanes were instead distributed to the active Groups in England (the 20th, 55th, 78th, 364th, and 479th) and the 56th received their second-hand H model aircraft, many beginning to show their age and the stresses of combat.
Still, Hilgert was happy to be back in the skies and was ready to get back to work. In the time he had been gone his once high-score of 16.83 had been passed by several other fighter jocks in the 8th. The target now was the 56th’s own Lt.Col. “Gabby” Gabreski’s 28 aerial victories—a tally the Lieutenant Colonel was not likely to increase any time soon since he was rotated back to the States when the 56th was pulled off active duty in preparation for the Lightning transition on July 14th.
Now, the way was open for Hilgert to clobber his way back up and show the 56th just what a Lightning could do.
1./SG 1
Flugplatz Hotsten, Westphalia, Prussia, Germany
The unit, formerly attached as a subordinate to the I Gruppe of Jagdgeschwader 1, was once more independent. After continued losses over the previous six months the attrition had become untenable and they had been pulled back from Dortmund to re-organize at the little used Hotsten airstrip near the Lower Saxony border. Of the original Sturmbock pilots from the previous fall, only four remained.
The old saying was, “Außerordentliche Übel erfordern außerordentliche Mittel” and these certainly were times of extraordinary ills. Oberleutnant Gerhard Limberg knew how desperate the air war over the Continent had become but even if he had not the evidences were parked along the grass field in front him: sixteen new airplanes of three different types, cobbled together like old shoes from bits found in the parts bins. Truly extraordinary remedies.
All sixteen aircraft were experimental, having been rushed to 1 Sturmstaffel for immediate use and evaluation. Rumor was that they had not even undergone complete flight testing—instead, after being found generally airworthy, the High Command determined that they would be best evaluated by the experienced pilots who would fly them. Officially, they were told it was to ensure the highest quality of machine to forward units once the most experienced pilots certified them but unofficially it was understood by Limberg and his comrades that there were no longer enough skilled pilots to supply full compliments to both active units and the test branch.
Eight were Focke-Wulf 190s. Six of these looked more-or-less similar to the Antons with which they were accustomed, although Limberg noted they were slightly longer in the nose with four-bladed airscrews and had a small scoop protruding from below and behind the cowl, just fore of the wing roots. The remaining two 190s were set apart by even longer noses as well as lengthened and broadened tails but their most striking features were the large pouch-like scoops under the fuselage. From this—or perhaps into this—pouch were partially exposed ducting running to and from the engine cowl.
If the odd appearance of the pouched 190s caught the attention of the pilots, it was quickly over-shadowed by the remaining eight airplanes—or, rather, four airplanes, Limberg corrected himself—for what at first he had taken to be eight new Messerschmitt 109s were actually four individual airplanes each made by joining two 109s together.
“Mein Gott,” Oberleutnant Hans Weik muttered just loud enough for Limberg to hear. The tone was clear and Limberg knew what was left unsaid.
They expect us to fly these into the fight?
8 August 1944
Those pilots with more experience in the Messerschmitt were given the 109 Zwilling aircraft. They were twin engine, twin fuselage heavy fighters with the single pilot in the left fuselage and the cockpit removed and faired over on the right side. They were quick, temporary, measures to get aircraft with firepower to bring down the American viermots with enough speed to outrun their Lightning and Mustang escorts.
The staffel had already lost one to an accident when the pilot, unused to dual-engine flying, lost the left engine on final and cartwheeled into the ground.
Limberg had been allowed to try some of the new Focke-Wulfs. The shorter-nosed variants, Bruno, were almost the same as his old Anton but with the engine replaced by a new BMW 801J Triebwerksanlage originally intended for the Junkers 388. These air-cooled radials were different from the standard 801s by being fitted with a Turbolader behind the engine, the charge air cooled by a small intercooler in the external scoop under the Kraftei. Three of these Brunos were additionally enhanced by having slightly larger wings with an extra two square meters of area for better high-altitude performance and also had pressurized cockpits.
The other two, which were officially Cäser models but which the pilots had started to call Känguruh because of the large pouch under the fuselage, had the air-cooled BMW engine replaced with the massive Daimler DB 603 inverted V-12. These were also fed by a large intercooled Turbolader, with both the turbo and the intercooler housed in the large pouch. The exhaust stacks were combined on each side into long hot ducts which ran externally along the nose and then under the upper wing fillet and back out the rear of the wing and down to the pouch. The intake air ducts were likewise exposed from the front of the pouch from where they went back up into the lower engine cowling to feed the engine. These were also pressurized but lacked the larger wings of the three pressurized Bruno airplanes.
Of these, Limberg preferred the Bruno. While the Caesar was slightly faster, it also handled differently and had the tendency to nose over at lower speeds. The Bruno, on the other hand, flew much the same the Anton but with added assurance of the significant power increase and, the case of those with pressurized cockpits, more comfort where they would be needed above 6 kilometers.
Two of the Brunos were out-of-service, both having suffered engine damage as a result of turbo failures, and were awaiting replacements. In the meantime, Limberg had claimed one of the pressurized B-4 airplanes as his own, now painted with his White-8, and he worked with his maintenance crew to apply a Rüstastz kit from his last Sturmbock to the airplane. The work included replacing the 7.92mm MG 17 cowl guns with 13mm MG 131s and the 20mm MG 151/20 outer-wing cannons with 30mm MK 108s as well as adding the heavy 30mm canopy and windscreen armor and 5mm cockpit armor. The resulting airplane, Fw.190B-4/R1, was one that Limberg felt may actually have a chance at fulfilling its role as a bomber destroyer and still get him home safe from the American fighters—even after adding the weight of the armor and larger guns he was able to push it over 700km/h at 8 km altitude using MW50 boost.
The Kangaroos and Zwillings were even faster. Weik had reported that he pushed one of the Caesars past 720km/h at 7000 meters without over-speeding the turbo, meaning there may be even more power available. Hauptman Walter Rödl had claimed to hit nearly 750km/h in Zwilling Black-3 just two days earlier at 8 km.
Now that they had proven they could fly the experimental aircraft they were being sent back to Dortmund to join the Fw.190 Sturmbocke of II Sturmgruppe of JG 300 to try them in combat.
10 August 1944
61 FS, 56 FG, 65 FW, 8 AF
AAF-150 (RAF Boxted), Essex, England
Captain Donald Hilgert had been back in England for nearly a month now.
After six months back in the States for leave and training when his first tour ended he shipped out in early July to his new assignment as Deputy Squadron Commander of the 61st Fighter Squadron of the 56th Fighter Wing as part of their transition from P-47s to P-38s, the last Group in the 8th Air Force scheduled to do so. Once the 56th is up and operational with P-38s, each Fighter Wing in VIII Fighter Command will be composed of three Groups of P-51s and two of P-38s. With each Wing attached directly to one of the three Air Divisions, then each Group of Bombers will be afforded equal protection.
The transition was scheduled to correspond with the end of tour for most of the existing 56th pilots, allowing them to backfill the needed personnel from P-38 qualified pilots taken from stateside Groups and rotating experienced pilots, like Hilgert, back for a second tour. The remaining P-47 pilots would receive transition training to the P-38 over the four weeks planned from mid-July to mid-August.
The other P-38 Group in the Wing, the 479th, was lucky enough to come with their own aircraft and so received the new P-38K. Hilgert’s 56th Group was not so fortunate. The new airplanes were instead distributed to the active Groups in England (the 20th, 55th, 78th, 364th, and 479th) and the 56th received their second-hand H model aircraft, many beginning to show their age and the stresses of combat.
Still, Hilgert was happy to be back in the skies and was ready to get back to work. In the time he had been gone his once high-score of 16.83 had been passed by several other fighter jocks in the 8th. The target now was the 56th’s own Lt.Col. “Gabby” Gabreski’s 28 aerial victories—a tally the Lieutenant Colonel was not likely to increase any time soon since he was rotated back to the States when the 56th was pulled off active duty in preparation for the Lightning transition on July 14th.
Now, the way was open for Hilgert to clobber his way back up and show the 56th just what a Lightning could do.
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@EverKing It's really great to see this latest chapter posted. It's also going to be interesting to see the results of the combats between Hilgerts' squadron and the Luftwaffes' Zwillings and Turbocharged Focke Wulfs. They sound like real beasts and fast as hell.
The newly transitioned 61st squadron and the rest of the 56th group pilots may end up wishing they had been issued new P-38Ks instead of worn out Hs. If they're facing Luftwaffe experten in these Zwillings and new model 190s the Americans may need every advantage they can get. Time and Chapter 36(b) will tell.
The newly transitioned 61st squadron and the rest of the 56th group pilots may end up wishing they had been issued new P-38Ks instead of worn out Hs. If they're facing Luftwaffe experten in these Zwillings and new model 190s the Americans may need every advantage they can get. Time and Chapter 36(b) will tell.
Welcome back.
I must say, it's with unusual brevity.
That said, I share Draconis' view, in the main: the turbo 190s could be very challenging beasts, indeed.
When they work, that is... I have a sense the kludge factor means they will suffer poor serviceability, compared even the the Hs of the 56th; IMO, that numerical edge will balance the performance disadvantage: I don't see that being great enough to make it a fair fight.By the time the 190C is sorted, I expect the war to be over.
As for the 109Z, In some conditions, it may be a tough opponent to avoid, or (more probably) catch, but somehow, I picture the twin fuselages going their separate ways in high-gee pullouts...
This will not pertain to the P-38s, obviously, so...However, I may well be wrong.
(It would not be the first time. )As I said, just setting the stage.
They certainly have the potential. I was originally going to skip them entirely and focus exclusively on the Zwilling but several people made a good point about German attitudes toward twin-engine fighters so I had to re-think it. Then, I was going to only include the 190C, skipping over the 190B entirely until I read about the Ju.388 using Kraftei BMW 801Js with turbochargers (apparently mounted at the top-rear of engine at a 30 degree angle and fully incorporated into the package). That about 100 Ju.388s with the 801J became operational between summer '44 and the end of the war it seemed to me that the LW could easily transfer some of these resources and build two 190Bs for every 388 with minimal changes to the rest of production. This, then, seemed to me to be the quickest way to match the Americans (excluding the P-38J/K which are still just trickling in, except with the 479th).
I think they will run into the same problems as all of the other platforms planned for the DB 603 with engine production and availability. If the 190B proves successful, I expect the 190C to be abandoned as a failed project. This could also mean the 190D never comes about, with FW R&D instead directed entirely toward the Ta-152 and, later, a jet interceptor similar either to the Ta-183 (or, in rocket-powered form the FW Volksjaeger 2) or the FW Volksjaeger 1.
It is an expedient way to get speed and performance, but yes...in maneuvers it may discover some weaknesses. Regardless, it is simply a stop-gap until the delayed 262 can become available.
Of course, all the LW plans may change as they learn more about the P-38J/K series and as they have to face more of them. I have some ideas around their solution to that problem and it is rather...interesting.